In installing electrical fixtures, receptacles, lights and the like on the exterior of a building wall, it is necessary to provide a means of preventing rain from entering into the wall past the siding. Typically, various central boxes are used which are designed to shield against the entry of rain. A typical mounting box has a perimeter nailing strip with nail holes to allow nailing of the mounting box to the surface of the sheathing covering the outside of the wall. The mounting box extends outwardly from the nailing strip. Exterior cladding or siding is placed over the nailing strip abutting the mounting box and a cover plate snaps over the mounting box abutting the siding. The mounting box deflects water to the sides but prior devices had no reliable way of further diverting the water flowing to the sides down the vertical sides of the mounting box and onto the siding below. Without such a feature water enters between the cladding and the sheathing where it can cause damage to the structural framework of the building. Even in systems such as that described in U.S. Pat. No. 6,951,081 issued to Bonshor which provides vertical channels formed between spaced apart flanges located on either side of the mounting box for the water to run down, water will still flow around the flange and into the region between the sheathing and the cladding.
U.S. Pat. No. 5,303,522 issued to Vagedes discloses a tab extending from partway down the nailing strip at an inclined angle towards an outside flange. Any water getting into the channel is supposed to run along the tab and away from the building wall to an exterior surface of the siding. The problem with Vagedes is that there is nothing to divert the water flowing to the sides along the top of the mounting box down to the tab. As a result water flowing to the sides enters the region between the sheathing and the cladding almost unimpeded.
Accordingly, it is an object of the invention to provide a water deflection system for a mounting box that constrains all of the water flowing onto a mounting box so that it flows down each side channel adjacent to the mounting box without penetrating the region between the sheathing and the cladding.